Fuel feed device



May 2, 1939. G R. ERICSON FUEL FEED DEVICE Filed Feb. 20, 1937 65026.:E. fe/cso/v INVENTOR.

ATTORNEY.

Patented May 2, 1939 UNITED STATES PATENT OFFICE FUEL FEED DEVICEApplication February 20, 1937, Serial No. 126,947

2 Claims.

This invention relates to liquid feed means and is applicable moreparticularly for delivering fuel to internal combustion enginecarburetors where no constant level chamber or pump is provided.

Small stationary internal combustion engines,

such as are used for operating generators in isolated places, arefrequently provided with separate carburetors mounted in connection withthe fuel storage tank. Where the carburetor suction alone is relied uponto deliver fuel from an atmospheric tank, the rate of fuel delivery isobviously dependent upon the depth of the liquid in the tank and,accordingly, the fuel and air mixture provided with such an arrangementbecomes gradually leaner, resulting in loss of power, and may cause theengine to stop before the tank is drained unless an adjustment is made.

An object of the present invention is to provide means for delivering aliquid, such as gasoline or other fuel, at a uniform rate from a storagetank to a source of intermittent suction outside the tank.

A more detailed object is to provide a measuring valve device fordelivering fuel at a uniform rate to an internal combustion engineirrespective of the depth of fuel in the storage tank.

These objects and other more detailed objects hereafter appearing, areattained substantially by the structure illustrated in the accompanyingdrawing, in which:

Figure 1 is a sectional view of a carburetor and storage tank assemblyembodying the invention.

Figure 2 is a detail longitudinal section showing the delivery devicewith the plunger valve in a different position.

Figure 3 is a horizontal section taken on line 3-3 of Figure 1.

The figures show a carburetor having a horizontal Venturi-shaped mixtureconduit I, secured at one end to a tube 2 for connection with the intakeof an internal combustion engine. At the opposite end of the carburetoris a cap valve 3, having slots 4 for cooperating with slots 5 in thecarburetor for manual control of the air admitted thereto. A fueldelivery orifice 6 opens into the throat of the venturi and iscontrolled by a needle valve 1. The carburetor also has a base portion 8secured to a pad 9 on top of fuel tank I0.

A tubular passage member II is threadedly secured at its upper end inthe enlarged lower portion of carburetor fuel orifice 6, as at Ila, andextends through the tank cover well downwardly into the tank. The tankis also provided with a filling opening l2 having a cover l3 with a holeI4 for exposing the interior of the tank to atmosphere.

At the lower end of passage member I there is threadedly secured achambered extension I5 having an inlet opening l6 controlled by inletcheck 5 ball I1. A coiled spring l8 constantly urges the ball l1 againstits seat in inlet l6 and at its upper end is seated against a separateshoulder stop l9 secured between the end of passage member II and theextension member. The central bore 20 10 in passage member I is enlargedat its lower end to form a chamber 2| which, at its lower endcommunicates with chamber 22 in member I 5 through central orifice 23 instop member I9.

Movably received in chamber 2| is a plunger 5 valve 24 having a taperedlower end 25 for seating against stop member H1 at the lower end of theplunger stroke and a tapered upper portion 26 for seating against ashoulder 2| a in chamber 2| at the upper end of the plunger stroke.Plunger 24 20 is constantly urged downwardly by the coiled spring 21which extends into the hollow interior of the plunger and at its upperend seats against a shoulder at the very top of chamber 2|. Spring 21 ispreferably weaker than check spring I8. 5 Plunger valve 24 loosely fitswithin chamber 2| and is proportioned relative thereto so as toaccomplish its function as described hereafter.

In operation, suction pulsations from the engine are transmitted throughthe carburetor and bore 30 20 to chamber 2|, raising both plunger valve24 and inlet check |1 against springs 21 and I8 and drawing liquid fuelthrough openings l6 and 23 into chambers 22 and 2|. At the end of thesuction stroke, check |1 quickly closes inlet l6, trap- 35 ping liquidfuel in chambers 2| and 22 so that the downward movement of plungervalve 24 under the influence of spring 21 causes a quantity of fuel topass around the plunger and into the upper part of chamber 2 On the nextsucceeding suc- 40 tion stroke, plunger 24 is drawn upwardly againstshoulder 21 (Fig. 2) lifting this quantity of fuel into bore 20 andeventually when the bore is filled, fuel is delivered to the carburetor.When the plunger valve is against its upper valve seat, com- 45munication between the tank and carburetor is sealed, preventing furtherdelivery of fuel.

The space between stop member l9 and shoulder 21 and between plungervalve 24 and the wall of chamber 2| is made sufiicient to permit an ade-50 quate delivery of fuel for the needs of the associated engine whenthe fuel level is near the bottom of the tank, and to insure fullmovement of the plunger valve under this condition. A uniform quantityof fuel is forced above the plunger 55 iii) valve during each downwardstroke thereof under the impulsion of spring 21 and this quantity onlyis delivered to the carburetor during each suction stroke. Needle valve1 provides an additional adjustment which, however, may be omitted wherecheapness and simplicity are essential. Relatively low suction isapplied to the fuel on each stroke of a small stationary engine of thetype for which the present invention is especially adapted and theweight and stroke of plunger 24 must be correspondingly calibrated.

From the above description it is apparent that the stroke of plungervalve 24 remains constant regardless of the pressure differences betweenthe tank and the carburetor, as long as this difference is sufiicient tocause the plunger to move its full stroke. Thus a uniform quantity ofliquid fuel will be delivered to the carburetor regardless of the fuelhead in the tank whereby the fuel tank may be drained and refilledwithout affecting the fuel delivery and without readjustment of theneedle valve or of the air valve 3 other than may be necessary for coldstarting.

The invention is not limited to the structure shown, but may be modifiedin various respects as will occur to those skilled in the art, and theexclusive use of all such modifications as come within the scope of theappended claims is contemplated.

I claim:

1. In combination with an internal combustion engine, a suction conduitand a fuel storage tank, structure connecting said conduit and said tankincluding a passage terminating near the bottom of said tank, an inletcheck at the bottom of said passage, spaced valve seats above saidcheck, and a plunger valve movable between said seats and proportionedrelative to the space therebetween so that when suction is applied tosaid passage, said plunger valve is drawn upwardly against the upper ofsaid seats restricting the quantity of liquid drawn into said conduitand at the end of the suction pulsation said plunger valve drops to thelower of said seats, said inlet check maintaining a full column ofliquid in said passage during dropping of said plunger valve.

2. The combination of elements specified in claim 1 further including aspring constantly urging said plunger valve toward the lower of saidvalve seats and a stronger spring constantly urging said inlet checktoward its closed position.

GEORGE R. ERICSON.

